Improved capstan



UNITED STATES PATENT OFFICE.

JACOB EDSON, OF BOSTON, MASSACHUSETTS.

lMPROVED CAPSTAN.

Specification forming part of Letters Patent No. 57,302, dated August21, 1866.

To all whom it may concern:

Be it known that I, JACOB EDSON, of Boston, in the county of Suffolk andState of Massachusetts, have invented certain new and usefulImprovements in Capstans; and I do hereby declare that the followingdescription, taken in connection with the accompanying plate ofdrawings, hereinafter referred to, forms a full and exact specificationof the same, wherein I have set forth the nature and principles of mysaid improvements, by which my invention may be distinguished from allothers of a similar class, together with such parts as I claim anddesire to have secured to me by Letters Patent. Y

The presentinvention relates to certain new and useful improvements incapstans, and has for its object the arrangement of its several devicesin such a manner as to produce acapstan more perfect in its operation,more economical in its wear and cost, and more satisfactory in itsgeneral use than those heretofore employed.

My improvements consist- First, in forming the head in which therunning-gears are placed and heldin two disks, united bysustaining-bridges, the two disks being cast and united so as to formone piece.

Second, constructing the ratchet and gear plate and the gear thatengages with the other.

gears in one piece-that is, so that they do not have to runindependently of each other, and so as to make the communication direct.This can be done by bolting, casting, or otherwise.

Third, casting the base and shaft or spindle of the capstan hollow andin one piece, by which means all liability of the shrinking' andcracking of the sha-ft or spindle when cooling, after being cast, isprevented. Moreover, a wrought-iron spindle requires a very heavy baseof cast-iron to receive it, is cumbersome and expensive, and the base,containing such a weight of metal, is liable to the same objection ofshrinking and cracking.

I will now proceed to describe in detail the arrangement and operationof my improved capstan.

The accompanying plate of drawings represents my improvements.

Figure l is a central vertical section of my improved capstan. Fig. 2 isa top view of the same with the cap removed; and Fig. 3A is a detailview, showing the gears, &c.

a c a, in the drawings represent a base, and b b the shaft or spindle,of a capstan, cast in one piece, and formed hollow and of the shapeshown in Fig. 1. Over the shaft or spindle b b is placed an outer caseor body, c c, of a capstan, the inside of the lower portion of which isformed of a conical shape to corresponde with the bottom 'of the spindleb b, over which it revolves. Through the center or hollow portion of thecase c c the shaft or spindle b b passes. The upper portion of the bodyor case c o is so formed as to receive a disk or plate, e c, whichpasses over the shaft or spindle b b, and is prevented from turningthereon by means of a stop-piece, ff, formed on the shaft b b, fittinginto a slot, g g, formed in the inner periphery of the disk or plate cc.

Connected with the plate c c, by means of bridges h h, is a ring orplate,z' fi, the plates e c and c' i and the bridges h h being cast inone piece. Between the two plates c c and i i, revolving on pivots k k,attached to the said plates, is a series of gear-wheels, l l, whichengage with a rack, m m, formed 011 the inner circumference of the upperpart of the case or body c c, and also with a gear-wheel, n fn, whichpasses through the opening formed by the ring or plate c' i, and isformed onto the bottom of a disk or plate, 0 o, on the upper portion ofwhose circumference ratchets p p are formed. On the top of the outer rimof the case or body c c ratchets q q are also formed. Engaging with theratchets p p and q q, which operate in opposite directions to eachother, are pawls r r and s s, pivoted to each side of an arm, t t, whichforms one of a series of arms, t t, connected with a circular band, u u,that extends over and revolves round the top of the case or body c c.Apertures c c are formed through the circumference of the band u u andin the ends of the arms t t, for the admission of levers for operatingthe capstan. The shaft b b extends up through the several plates to thetop of the arms t t, where it is The pawl-seats formed in the under sideof the arm t t, on each side ot' the apertures 'v fu, are so arrangedthat long bearings are given to the pawls r .r and s s, thus increasingtheir strength, keeping them in correct position, and at the same timeallowing them to play freely in the said seats.

By the foregoing description, reference being made to the drawings, itwill be seen that when power is applied to the arms t t the pawls rr andss engage with or are disengaged from the ratchets p p and q q,according to the direction in which the arms t t are turned. Forexample, by turning the arms t t to the right the pawlr r engages withthe ratchets p p ot the plate o o, and the pawl s s is consequentlyfreed from the ratchets q q, which are formed at an opposite angle withthe ratchets p p, thereby revolving the plate o 0 and the gearwheel n n,which revolves the gear-wheels l l, that engage with the rack m m, androtates the case or body c c of the capstan, thus increasing the powerof the capstan'and lessening the exertion required in its operation.

By turning the arms t t in an opposite direction the `pawl s s engages'with the ratchets q g, and the pawl r r is loosened from the ratchets pp, and the power is directly communicated to the case or body c c of thecapstan, as in ordinary cases, thereby increasing the speed anddiminishing the power with which the capstan is operated.

By turning the arms t t a little way back and forth in each directionthe capstan may be operated by a person standing in one position withoutthe necessity of his traveling around it.

Formerly, in changing the operation ot' a power-capstan to that of asimple one, it was necessary to disconnect the gears, which, from wantof use, were liable to rust or become otherwise inoperative. By myimprovement-s the gears are used either way the capstan is operated, andare therefore kept in constant Working order.

It will be observed that there can be no strain on the bearings of thegears l Z, because they are wholly independent of the eoniiningplates ee and i z', in which they run; whereas, if' they were bolted, as usual,between two plates, (the bolts forming the journals of' the -gears,) theplates would be liable to spring' and warp and throw the journals out ofposition; but at the same time it is evident that an upper and lowerbearing are necessary to form bearings to the surface of the gears tokeep them in their horizontal position orplay, which the above-describedarrangement secures.

Having thus described my improvements, I shall state my claims asfollows:

What I claim as m-y invention., and desire to have secured to me byLetters Patent, is-

l. The combination of the pawls r r and s s, so arranged as to -operatein opposite directions with each other, with the ratchet or toothedplate o o and ratchets q q, as hereinabove described, and for thepurpose specified.

2. In a capstan, forming the head in which vthe running-gears are placedin two disks,

united by sustaining-bridges', the two disks being united so as to formsubstantially one piece, as specied.

3. In a capstan, constructing the ratchet or toothed plate o o and gearu n in one piece, as described.

- 4. .In a capstan, casting the base a a and shaft or spindle b b hollowand in one piece, as specified.

'JACOB ED SON;

